MDL-43598 dialogue: fixed bug with render procedure

Conflicts:
	lib/yui/build/moodle-core-notification-dialogue/moodle-core-notification-dialogue-debug.js
	lib/yui/build/moodle-core-notification-dialogue/moodle-core-notification-dialogue-min.js
	lib/yui/build/moodle-core-notification-dialogue/moodle-core-notification-dialogue.js
	lib/yui/src/notification/js/dialogue.js
MDL-43664 Javascript: Use YUI indexOf for pending_js tracking

Some old browsers do not support indexOf and so cannot determine whether JS
script is in progress. The YUI Y.Array module polyfills the indexOf
functionality when it does not exist.
MDL-42928 JavaScript: Create a module to handle page scroll locking
MDL-42928 JavaScript: Add LockScroll to all modal dialogues
MDL-42928 JavaScript: Disable lockScroll for small chooserdialogues